1. Field of the Invention
The present invention relates to a multi-dimensional Fourier transform parallel processing method for a shared memory type scalar parallel computer.
2. Description of the Related Art
A multi-dimensional Fourier transform for a vector computer has been developed so that the vector length becomes as long as possible. In particular, to perform a high-order Fourier transform such as three dimensional Fourier transform, an algorithm of which a vector length is represented by n1×n2 is used (where n1 and n2 are lengths of data of respective one-dimensional directions).
For fully using the function of a RISC scalar processor, it is important to store data in a cache and reuse the stored data. Thus, before the first dimensional data is Fourier transformed, it is transposed so that the first dimensional data becomes the third dimensional data. Thereafter, the transformed data is re-transposed.
A one-dimensional Fourier transform used in a three-dimensional Fourier transform is performed in such a manner that the vector length becomes long.
However, in a shared memory type scalar parallel computer, unless data stored in a primary cache memory and a secondary cache memory is effectively used and calculated, data is frequently exchanged between a shared memory and a processor. Thus, the resultant overhead becomes large.